law inforcement sources say they exchanged gunfire with the suspect. a neighbor caught the fire fight on video. >> ultimately, the hostage rescue team or the fbi made an entry into the boat and removed the suspect, who was still alive, in the boat. >> the standoff came almost 24 hours after believe to have killed a police officer at the massachusetts institute of technology. that led to a fierce fire fight in police in watertown that killed tamerlan and may have injured his brother. it has been a long day for the people here in watertown and in the greater boston area. the search for the tsarnaev brothers have closed schools and offices and shut down the entire area. president obama expressed his thanks from the white house. >> we owe a tremendous debt of gratitude to all our outstanding law enforcement officials. >> the fbi marked captured and in boston scores of people gathered for a candle light vigil near the finish line of the marathon. in addition to motive, the authorities will also be looking to see if these two brothers were working alone or p